Enum TxnDBWritePolicy 

pub enum TxnDBWritePolicy {
    WriteCommitted = 0,
    WritePrepared = 1,
    WriteUnprepared = 2,
}

When a TransactionDB writes transaction data into the DB.

TransactionDB reads this once while opening, to choose which implementation to build, and keeps its own copy. Changing it on a TransactionDBOptions afterwards has no effect on a DB that is already open.

Variants

WriteCommitted = 0

Write data at commit time.

Only committed data ever reaches the DB, so readers need no extra machinery to tell committed from uncommitted. This is the default.

WritePrepared = 1

Write data after the prepare phase of two-phase commit.

Data lands before the commit, so the DB has to track which of it is committed and readers have to consult that. Experimental: RocksDB describes the non-committed policies as less mature, less validated and less compatible with other features than WriteCommitted.

WriteUnprepared = 2

Write data before the prepare phase of two-phase commit.

A running transaction can flush its pending writes into the DB once its batch crosses TransactionDBOptions::set_default_write_batch_flush_threshold, which keeps memory bounded for very large transactions. Experimental, and the least mature of the three.

Trait Implementations

impl Clone for TxnDBWritePolicy

fn clone(&self) -> TxnDBWritePolicy

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for TxnDBWritePolicy

impl Debug for TxnDBWritePolicy

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for TxnDBWritePolicy

Available on crate feature serde1 only.

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for TxnDBWritePolicy

impl PartialEq for TxnDBWritePolicy

fn eq(&self, other: &TxnDBWritePolicy) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for TxnDBWritePolicy

Available on crate feature serde1 only.

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for TxnDBWritePolicy